The present invention relates to a changer-type disk playback device capable of selectively playing back a plurality of disks stored in a stocker.
In Japanese patent application 7-72281 (Japanese laid-open publication number 8-241552), the present applicant proposed on internally mounted changer-type disk playback device having outer dimensions that conform to the 51/4 inch half-height form factor and that is capable of being attached to the main unit of a computer.
Referring to FIG. 7 and FIG. 8, a stocker 41 capable of holding four disks in the rear of the device is disposed so that it can move up and down. A disk is inserted through a disk insertion opening 1A and played back. By storing disks in stocker 41, the device can selectively play back the disks held in stocker 41.
Of course, there is a desire for an internally mounted changer-type disk playback device that can hold an increased number of disks within the half-height form factor. A number of attempts to do this have been made, but for each additional stored disk, the vertical displacement range of stocker 41 must increase by an amount corresponding to the disk pitch distance (3 mm).
In FIG. 7, stocker 41 is moved down as far as it can go. The downward movement is limited by the size of the casing.
Referring to FIG. 8, stocker 41 cannot be moved further upward in the device.
Referring to FIG. 9, a disk transfer plane S could be moved down by a distance corresponding to the disk pitch distance, i.e., 3 mm, thus increasing the displacement range of stocker 41 downward by 6 mm.
However, when disk transfer plane S is lowered by 3 mm, a disk playback mechanism 500 must also be lowered by the same distance. This results in a narrowing of the gap between disk playback mechanism 500 and a printed circuit board 240, which is attached to the bottom surface of the device. This creates new problems, with disk playback mechanism 500 getting in the way of electronic parts 300, which are relatively elevated (approximately 6 mm) and are attached to printed circuit board 240 near the back surface of a device front panel 1. Electronic parts 300 can include a disk eject switch, a headphone terminal, a headphone volume control, and the like.
Referring to FIG. 10, it would also be possible to decrease the disk pitch from 3 mm to 2.25 mm in order to avoid increasing the displacement stroke range of stocker 41 while accommodating additional disks. However, this would result in the gap between adjacent disks held in the stocker being decreased from 1.8 mm to 1.05 mm. If disks are loose within the stocker, the front side of a stocker disk may slope downward, resulting in contact between a playback disk D5 at a playback position and a disk D4 held in the stocker at a position above playback disk D5. This could cause damage to the disks.